<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>
<head>
  <meta name="generator" content=
  "HTML Tidy for Linux/x86 (vers 1 September 2005), see www.w3.org">

  <title>find_first_of</title>
  <link href="../cppreference.css" rel="stylesheet" type="text/css">
</head>

<body>
<table>
  <tr>
  <td>
  <div class="body-content">

  <div class="header-box">
    <a href="../index.html">cppreference.com</a> &gt; <a href=
    "index.html">C++ Strings</a> &gt; <a href=
    "find_first_of.html">find_first_of</a>
  </div>

  <div class="name-format">
    find_first_of
  </div>

  <div class="syntax-name-format">
    Syntax:
  </div>
  <pre class="syntax-box">
  #include &lt;string&gt;
  <strong>size_type</strong> find_first_of( const string &amp;str, <strong>size_type</strong> index = 0 );
  <strong>size_type</strong> find_first_of( const char* str, <strong>size_type</strong> index = 0 );
  <strong>size_type</strong> find_first_of( const char* str, <strong>size_type</strong> index, <strong>size_type</strong> num );
  <strong>size_type</strong> find_first_of( char ch, <strong>size_type</strong> index = 0 );
</pre>

  <p>The find_first_of() function either:</p>

  <ul>
    <li>returns the index of the first character within the current
    string that matches any character in <em>str</em>, beginning the
    search at <em>index</em>, string::npos if nothing is found,</li>

    <li>searches the current string, beginning at <em>index</em>, for
    any of the first <em>num</em> characters in <em>str</em>,
    returning the index in the current string of the first character
    found, or string::npos if no characters match,</li>

    <li>or returns the index of the first occurrence of <em>ch</em> in
    the current string, starting the search at <em>index</em>,
    string::npos if nothing is found.</li>
  </ul>

  <div class="related-name-format">
    Related topics:
  </div>

  <div class="related-content">
    <a href="find.html">find</a><br>
    <a href="find_first_not_of.html">find_first_not_of</a><br>
    <a href="find_last_not_of.html">find_last_not_of</a><br>
    <a href="find_last_of.html">find_last_of</a><br>
    <a href="rfind.html">rfind</a>
  </div>
  </div>
  </td>
  


  </tr>
  </table>
</body></html>
